1. Field of the Invention
This invention relates to mechanical prosthetic and therapeutic aids employed by disabled persons to restore independent mobility.
2. Description of Prior Art
In the course of institutionalization of the aged, infirm, or otherwise disabled, and in the process of recuperation from debilitating injuries and diseases, several types of ambulatory aides are in common use. For those who have lost all or most of their ambulating powers, wheel chairs provide total support, allowing mobility over smooth surfaces, propelled by hand motion for independent mobility. Walkers, consisting of a three sided frame, and four legs, usually tipped with rubber caps are also in widespread use. The individual lifts the frame, extends it forward with his arms, and, thus braced to maintain balance, walks for several steps. A version of this device has wheels on the front two legs, which allow the individual to push the device forward; otherwise, the ambulating process is the same. Here, upper body strength is required to lift the rear wheels of the walker, and push it forward--almost as much as lifting the entire frame. Patients commonly scoot the frame along the floor causing disturbing noises by friction between the rubber tips and the surface, and providing little benefits beyond standard walkers. Last are canes, which partially supplement the weakened leg during walking.
It has been recognized that a void exists between the wheel chair, which requires absolutely no ambulating powers, and the walker, which requires the ability to stand, balance, and totally support the weight of the body.
Several approaches are disclosed in patents. Discussed here are: Mueller, U.S. Pat. No. 4,621,804, Nov. 11, 1986; Stillings, U.S. Pat. No. 4,342,465, Aug. 3, 1982; Morris, et. al., U.S. Pat. No. 4,643,211, Feb. 17, 1987; Goldberg et. al., U.S. Pat. No. 3,488,088, Jan. 6, 1970; and Androw et. al., U.S. Pat. No. 3,778,052, Dec. 11, 1973.
Mueller, U.S. Pat. No. 4,621,804, Nov. 11, 1986, envisioned a single, flexible panel supported by horizontal bars front and rear. The illustrated embodiment of this device has four legs, each with swivel casters. This device has provisions for total support of the occupant, and removable, or retractable wheels for patients capable of limited self support. Obviously, the degree of disability requiring total support with this devise, i.e. suspended by a single crotch strap made of flexible material, puts the occupant at an severe disadvantage when attempting to propel him or herself.
For the extremely incapacitated, the entire weight is supported underneath the crotch, placing the occupant, particularly heavier patients, in painful, uncomfortable and potentially injurious position. In the less dramatic cases of disability, and in the initial stages of recovery from injuries, a stumble would result in the occupant falling either forward, or to one side, the center of gravity being above the support point. The device, in such a case, would continue to travel on its free wheeling casters, risking complete loss of vertical stability, seriously injuring the occupant with damage to the head, as well as the genitals.
With the casters removed, or retracted as described, the device is no more than a conventional walker, of the type in common use throughout the world, the design and utility of which is in the public domain.
In another approach, re Stillings, U.S. Pat. No. 4,342,465, Aug. 3, 1982, the rolling walker resembles the ones used by toddlers learning their first steps. The device envisioned in this patent has a framework which is in two sections hinged together at one side. The sections can be opened to permit entry of the handicapped person, whereupon the sections are rigidly locked together. A vertically adjustable seat is supported within the framework adjacent the rear portion, and the legs terminate in casters to permit the walker to roll along a smooth surface. Once the person is located in the device, a flexible, cushioned support cord is extended from the front of the seat, and attached to the forward, hinged portion of the frame. The support cord functions partially as a saddle, and partially as a support, should the patient stumble or fall. Said support cord, being essentially a single strap under the crotch, poses the same difficulties observed in Mueller. The seat, too, will interfere with normal walking motions, and inhibit the disabled from using it. Nor will the seat protect from injury, should the patient lose his or her balance, and fall backwards.
In Morris, et. al., U.S. Pat. No. 4,643,211, Feb. 17, 1987, a standard walker is equipped with casters on the forward legs, and a fold down seat. Here, the seat is intended to be used during rests between periods of ambulating, and not for support.
Goldberg et. al., U.S. Pat. No. 3,488,088, Jan. 6, 1970, describes a wheeled vehicle with a frame on three sides, and a bicycle-type seat mount attached to the upper and lower horizontal members of the frame via rigid bars. The seat itself is mounted on a vertical bar, and terminates with another swivel caster. The devise is presented as a therapeutic aid to obviate flexion contractures of selected body joints during convalescence. For feeble patients susceptible to falls, the horizontal members extending forward from the seat support bar present significant danger of injury to the crotch area. Nor is the height of the frame adjustable. Thus, this device is a form of scooter, and suitable strictly in those situations the inventor envisioned.
Most similar of all in concept and execution, is Androw et. al., U.S. Pat. No. 3,778,052, Dec. 11, 1973. Here, a complex harness arrangement is attached to the uppermost members of an open framework, which extends above the head of the occupant. As is common in all devises, the framework encloses three sides of the patient, and terminates in swivel casters. Here, however, the harness supports the waist, as well as the crotch, of the occupant, who is additionally aided by adjustable crutch heads, for positioning beneath the armpits of the patient. This structure is large and cumbersome, conceivably over seven feet in height, to accommodate taller people. The harness may become unstable, allowing the occupant to swing, and, if he or she releases the crutch heads, could fall into a completely upended position. The entire device could easily tip over. In this vision, the harness assembly involves a large number of straps, hooks, and buckles, causing it to be expensive to manufacture, and difficult to put on.
None of the prior art devices adequately fit the niche between the walker and the wheel chair.